An ultraconservative judiciary chief appears to have the only real chance of winning after a council of powerful clerics disqualified virtually all the other viable candidates.

TEHRAN — Come presidential election time, the streets of central Tehran are usually wallpapered with the candidates’ names and faces, their banners swaying from buildings and streetlights. But this time around, the biggest banners bear no names, only a simple message: Vote on Friday.

One common poster shows the bloody severed hand of Gen. Qassim Suleimani — the Iranian commander whose killing in an American drone strike in January 2020 brought throngs of Iranians into the streets in mourning — casting a white ballot.

“Do it for his sake,” the poster implores.

The message is unsubtle: Vote, and you support the Islamic Revolution for which General Suleimani gave his life. Don’t, and you undermine the whole system.

Since the revolution in 1979 toppled the monarchy, Iran has been run by parallel branches of the government. One is elected and the other is appointed, composed of the supreme leader and powerful councils of clerics.

While Iran has never been a true democracy over the past four decades, there was always a degree of choice and competition in elections for president and parliament. The outcomes were never a certainty.

But even those limited freedoms, which shrank after a contested election in 2009 led to widespread unrest, have nearly disappeared in this election cycle. The country is now moving increasingly toward what amounts to a one-party system whereby the top council of clerics that vets candidates eliminates anyone seen as a challenge to their conservative policies and views.

The Islamic Republic’s hierarchy has long used election turnout to try to bolster its legitimacy, pointing to robust voter participation as proof that Iranians really do choose their leaders. If voter turnout is low on Friday, that could be regarded as a sign of growing disaffection.

Iran’s supreme leader, Ayatollah Ali Khamenei, blamed Iran’s enemies and the foreign media for voter apathy in a live televised speech on Wednesday.

“The most important part of the elections is the people’s participation,” he said. “It means the Islamic Republic has the people’s support. There is no tool more powerful than voter participation.” He added that he “accepted the people’s complaints, but I do not accept not participating.”

A poster of presidential candidate Ebrahim Raisi.
Arash Khamooshi for The New York Times

Thus it was that Iman, 28, an information technology worker who was shopping for lamps in Tehran on Monday, said, “I will vote because the destiny of my nation is very important to me.”

He said he would vote for Ebrahim Raisi, the ultraconservative judiciary chief who appeared to have the only real chance of winning after the Guardian Council — the body of top clerics that vets the contenders — disqualified virtually all the other viable choices.

“You’re doing what? Really?” said his new wife Melika, 21, grabbing her husband’s arm in alarm. “If you vote for Raisi, we’re done,” she said, only half-joking. (Like some other voters interviewed for this article, they declined to give their full names, for fear of speaking too openly about politics.)

The wife rolled her eyes as her husband listed what he said were Mr. Raisi’s qualifications: promises to battle the corruption many Iranians say is crushing their economy; the forcefulness to stand up to the United States in renewed negotiations over limiting Iran’s nuclear program in exchange for lifting American sanctions, which are deepening those economic problems.

“I don’t believe in any of them,” said Melika, a computer engineer. “I’m just tired of all of it. I’m done.”

All across Tehran this week, Iranians were saying much the same thing.

“It’s absolutely hopeless,” said Reza, 33, a grocery store owner from Kermanshah, a city in western Iran, who had come to Tehran’s Grand Bazaar to shop for his upcoming wedding. “I have a problem with the whole system because I can’t express my opinions. The only way that I can show them I’m unhappy is by not voting.”

Arash Khamooshi for The New York Times

Many moderate-leaning Iranians appear to be planning to sit the election out, according to polls, commentary and interviews. They were already deeply disillusioned with candidates from the more moderate reformist movement who pledge to change Iran from within the existing system, rallying votes only to fail to deliver once elected.

But then the Guardian Council disqualified a number of prominent politicians — including the current vice president, former speaker of Parliament, a former president and a former minister — from both reformist and conservative factions.

That led many to conclude that the elections were engineered to produce victory for Mr. Raisi, known for his strict conservative views and what rights activists call a dire record of human rights abuses including mass executions. He has been sanctioned by the United States.

Mr. Raisi, 60, also is seen as an eventual successor to Mr. Khamenei, 81.

“Everything has already been set: The president has already been chosen,” said Nabiollah Razavi, 40, the manager of a popular restaurant in north Tehran who said none of his staff planned to vote. “There’s no difference for normal people, whether it’s a conservative or a reformist. Just look — the reformists were in power for eight years, and this is where we are.”

Mr. Razavi was referring to the outgoing president, Hassan Rouhani, regarded as a moderate who had promised social freedoms, economic improvements and better relations with the world because of the 2015 nuclear agreement, which has been at risk of collapse since President Donald Trump withdrew the United States three years ago.

Having entered the presidency on a wave of optimism, Mr. Rouhani will depart having failed to fulfill his pledges. Some of the worst crackdowns happened on his watch.

“We want the situation to get better,” Mr. Razavi said, “but as long as it’s the Islamic Republic, this is the way it’s going to be.”

Arash Khamooshi for The New York Times

After the authorities winnowed the candidates, a coalition of reformist parties announced for the first time that it would not endorse a candidate for president. Prominent figures from this coalition said openly that the elections were a sham.

But divisions have emerged over the past week, with reformist leaders sending conflicting messages.

Mir Hossein Mousavi, the leader of the Green Movement opposition party, who has been under house arrest since the unrest that erupted after his 2009 defeat in an election he described as rigged, issued a statement saying that the “republic” part of the Islamic Republic had lost its meaning. Mr. Mousavi said he stood with people “who are fed up with engineered and humiliating elections.”

In a statement issued Wednesday, more than 100 prominent reformist activists, dissidents and politicians called for people to boycott the vote and instead turn their grievances into peaceful disobedience.

But another reformist opposition leader under house arrest, Mehdi Karroubi, urged the public to cast ballots as the only means to “determine Iran’s fate under the current circumstances.” He endorsed Abdolnaser Hemmati, the former central bank governor, regarded as the only moderate left in the race.

A former reformist president, Mohammad Khatami, said on Wednesday that he hoped “people show resolve and participate” in elections to protest the predetermined result, according to Iranian media reports.

Also on Wednesday, a coalition of 15 reformist parties said they would vote and endorsed Mr. Hemmati to show they opposed the “dangerous orchestrated plan” for the election.

Mr. Hemmati, for his part, has said that his only electoral rival is voter apathy. If the public turned out in large numbers, he predicted, he will win.

“I know the president will have problems. They will interfere with his work. They will create obstacles for him. But it doesn’t mean we should leave the stage and not fight,” Mr. Hemmati said in an appearance on the social media platform Clubhouse on Wednesday night.

It remains possible that Mr. Raisi will not get the simple majority needed to avoid a runoff.

Arash Khamooshi for The New York Times

But the late endorsements for Mr. Hemmati were not expected to generate the kind of turnout that could end in an upset for Mr. Raisi. The most recent polls predict voter participation of about 42 percent, low for Iranian presidential races.

“If they think by calling for participation, people are going to come out, it’s a joke,” said Abbas Abdi, a political analyst who is close to the reformists.

At a Raisi rally in central Tehran on Wednesday evening, children set up chairs while volunteers distributed flags and cardboard visors that bore a picture of General Suleimani embracing Mr. Raisi.

As people waved Iranian flags and blue flags adorned with Mr. Suleimani’s face, a speaker told the audience that Mr. Raisi would eliminate all inequality in Iran and eradicate “the slightest speck of corruption.”

Two women in attendance said they respected Mr. Raisi’s qualifications as a judiciary head who had battled corruption in the past. But more than that, they said showing up was a patriotic duty.

“I want to show my support to the revolution,” said Zahra Shahrjerdi, 61, a retired teacher.

“There are problems in the Islamic Republic, but we believe the system is good,” said her daughter, Fatemeh Ghanaati, 35, a primary schoolteacher.

Others, however, had long since reached the opposite conclusion, that the problem was the Islamic Republic. Presidents might come and go, but the real power remained concentrated in the hands of the supreme leader and the Islamic Revolutionary Guards Corps, who some presidential candidates in this election have referred to as the “shadow government.”

“I voted for four different individuals in the past, and they couldn’t do the job,” said Zohre Afrouz, 58, a seamstress who said she could barely afford rent and had given up on ever buying a car despite 12-hour workdays.

She regretted her vote because no matter who the president is, “all of them are confined to a framework, and the policies are dictated to them,” she said. “My vote has no value.”

Amir, 30, a jewelry salesman at the Grand Bazaar, was blunter.

“Our country, it should be demolished and rebuilt,” he said. “It’s no use.”

Vivian Yee reported from Tehran, and Farnaz Fassihi from New York.